Modified atmosphere for food preservation

ABSTRACT

An appliance system including a module removably mounted to an appliance, one or more removable gas canisters operably connected to the module, and a food retaining enclosed space operably connected to the module. The one or more gas canisters supply a modified atmosphere in the food retaining enclosed space to produce a modified atmosphere that enhances preservation of the food contained in the food retaining enclosed space. A method of modifying the atmosphere in a food storage space for food includes the steps of: providing a module capable of being removably engaged to an appliance and typically receiving power from the appliance and at least one removable gas canister; operatively connecting or otherwise engaging the module with the appliance; operatively connecting or otherwise engaging the module to a food storage area having an existing atmosphere; and removing at least a portion of the existing atmosphere from the food storage space and replacing it with a modified food storage atmosphere using at least one of the at least one removable gas canisters to supply the modified atmosphere to the food storage area.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. §119(e) and the benefitof U.S. Provisional Patent Application No. 61/035,775 filed on Mar. 12,2008, entitled REFRIGERATOR WITH SPACE MANAGEMENT MODULES.

SUMMARY OF THE INVENTION

An embodiment of the present invention is generally directed to anappliance system that typically includes a food retaining space having avolume within the space; a module removably connectable to an appliance;and at least one compressed gas containing receptacle that includes allor a portion of a modified atmosphere to be added to the food retainingspace. The module typically includes a housing, a controlling device, aswitch, at least one valve, a vacuum pump, and a gas inlet wherein theswitch, the valve, and the vacuum pump are each in communication withthe controlling device (typically a microcontroller or a control boardin combination with a relay).

Another embodiment of the present invention includes a method ofproviding a modified atmosphere to a food storage space having a volumefor enhancing the preservation of food stored in the food storage spacewhen the food storage space contains the food and the modifiedatmosphere. Typically the method includes the steps of: providing a foodstorage space having a volume within the food storage space, a moduleremovably connectable to an appliance, and at least one compressed gascontaining receptacle that includes all or a portion of a modifiedatmosphere to be added to the food storage space; engaging the foodstorage space with the module such that gas is allowed to flow into andout of the volume within the food storage space; activating the moduleto remove ambient gas within the food storage space until apredetermined vacuum level is reached, allowing gas to flow from thecompressed gas containing receptacle into the food storage space tothereby create a modified atmosphere within the food storage space; andsealing the modified atmosphere and any food within the food storagespace within the food storage space. The module typically includes ahousing, a controlling device, a switch, at least one valve, a vacuumpump, and a gas inlet where the switch, the valve, and the vacuum pumpare each in communication with the controlling device and where a valveis positioned between the gas inlet and the switch, the food storagespace and the vacuum pump such that compressed gas cannot flow past thevalve when the valve is in the closed position and compressed gas canflow into the food storage space when the valve is in the open position;

Yet another embodiment includes an appliance system that includes a foodretaining space having a volume within the space; and a module removablyconnectable to an appliance and at least one compressed gas-containingreceptacle. The module typically includes a housing, a controllingdevice, a switch, at least one valve, a vacuum pump, and a gas inlet.The switch, the valve, and the vacuum pump are typically each incommunication with the controlling device and the valve is typicallypositioned between the gas containing receptacle inlet and the switch,the food retaining space and the vacuum pump such that compressed gascannot flow past the valve when the valve is in the closed position andcompressed gas can flow into the food retaining space when the valve isin the open position. The at least one compressed gas containingreceptacle may include a predetermined blend of gases for a given typeof food product. The food product is typically a meat product, a dairyproduct, a fruit product, a vegetable product, and a fish product. Thetypical modified atmosphere for a meat product contains about 70% byvolume oxygen, about 20% by volume carbon dioxide, and about 10% byvolume nitrogen. The typical modified atmosphere for a fish productcontains about 40% by volume carbon dioxide and about 60% by volumenitrogen. The typical modified atmosphere for fruits or vegetablescontains from about 3% to about 10% by volume oxygen, from about 3% toabout 10% by volume carbon dioxide, and from about 80% to about 94% byvolume nitrogen. The typical modified atmosphere for dairy productscontains from about 10% to about 30% by volume carbon dioxide and fromabout 70% to about 90% by volume nitrogen.

These and other features, advantages, and objects of the presentinvention will be further understood and appreciated by those skilled inthe art by reference to the following specification, claims, andappended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevated perspective view of an embodiment of a module ofthe present invention;

FIG. 2 is an elevated front view of an embodiment of a module of thepresent invention;

FIG. 3 is an elevated rear view of an embodiment of a module of thepresent invention;

FIG. 4 is an elevated rear view of an embodiment of a module of thepresent invention with the rearward cover of the upper portion of themodule removed;

FIG. 5 is an elevated front view of a side-by-side refrigerator/freezerappliance with a module according to an embodiment of the presentinvention engaged to the inner door liner surface of the refrigeratorsection of the appliance;

FIG. 6 is an elevated front view of a side-by-side refrigerator/freezerappliance with a module according to an embodiment of the presentinvention engaged to the outer door surface of the appliance;

FIG. 7 is an elevated view of another embodiment of the presentinvention where the module receives power from the appliance using anelectrical umbilical connection between the module and the appliance;

FIG. 8 is an embodiment of the present invention showing the use of onevalve to regulate flow of the gas into and out of the food retainingcompartment/space with the valve in the closed position to not allow gasto flow from the gas canister and depicting the gas being removed fromthe compartment/space;

FIG. 9 is the embodiment of the present invention shown in FIG. 8 withthe valve in the open position with gas from the canister being suppliedto the food retaining compartment/space;

FIG. 10 is the embodiment of the present invention shown in FIGS. 8-9with a second valve positioned between proximate the vacuum pump andproximate the compressed gas canister showing the system in the ambientgas removal mode;

FIG. 11 is the embodiment of the present invention shown in FIG. 10showing the system supplying modified atmosphere to the food retainingcompartment/space with the valve proximate the compressed gas in theopen position and the valve proximate the vacuum pump in the closedposition;

FIG. 12 is another embodiment of the present invention showing aplurality of gas canisters in the ambient gas removal mode;

FIG. 13 is another embodiment of the present invention showing multiplecompressed gas canisters that can be connected through one inlet tosupply the modified atmosphere;

FIG. 14 shows a pressure v. time curve where the opening time of themodified atmosphere supplying valve (T₂−T₁) depends on the emptying time(T₁−T₀) and is calculated to have only a fraction of atmosphericpressure within the food retaining compartment/space when the modifiedatmosphere has been supplied to the food retaining compartment/space.

FIG. 15 shows a pressure v. time curve where the opening time for thevalves (T₂−T₁) depends on the emptying time (T₁−T₀) and the valvesproximate a plurality of gas canisters (a,b,c) are opened for acalculated time in order to build a predetermined partial pressure ofgases that form a predetermined blend of gases that make up a modifiedatmosphere;

FIG. 16 shows a flowchart of a system for supplying a modifiedatmosphere to a rigid food retaining compartment/space according to anembodiment of the present invention; and

FIG. 17 shows a flowchart of a system for supplying a modifiedatmosphere to a food retaining bag according to an embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention generally relates to a removably connectablemodule that forms part of an appliance system. As shown in FIGS. 1-2,the appliance system typically contains a module 12 capable of forming amodified atmosphere within a food retaining compartment/space that has avolume in an appliance and/or façade or module receiving housing thatcan sit on a countertop and either be powered using a direct connectionor an umbilical-type power connection 11 or electrically connected to astandard electrical socket when the module receiving housing and themodule are placed on a countertop or the like. Typically, the appliance10 is a refrigerator, but conceivably could be any appliance such as arefrigerator and freezer combination, refrigerator, or freezer alone orcould also be a refrigerated space that receives cooler air from anothersource such as a freezer compartment. Most preferably, the appliancecontains a refrigerator compartment that has an inner liner. Whether atraditional appliance or a refrigerated space, the appliance typicallyis capable of providing electrical power to the module when the moduleis operatively connected to the appliance. Generally speaking, themodule operates to evacuate the food retaining compartment/space(typically a container, bag or other compartment/space 14). When thefood retaining compartment/space is a bag, it may be a heat-sealable bagand the bag may also optionally be either of fixed volume or expandable.When the food retaining compartment/space is a fixed volume container, afixed geometry container or a fixed volume compartment within themodule, the compartment typically has one or more valves.

The modified atmosphere injected into the food containingcompartment/space 14 extends the freshness of refrigerated food. Theatmosphere selected is customizable so that it best extends the life ofthe food or food group that the consumer wishes to extend the lifethereof.

The modified atmosphere module generally includes a housing 16 and acontrol device 18 typically positioned within the housing. The housingtypically contains an upper portion 20 and a lower portion 22 with thecontrol device typically contained within the upper portion 20 of thehousing 16 as well as two sides 24, a bottom surface 26 and a topsurface 28. The sides typically have at least one, more typically aplurality, substantially T-shaped appliance-receiving groove 30 that isformed by a raised substantially T-shaped portion 32 along the perimeterof the groove 30. This configuration operates by engaging matingelements of the appliance to retain the module in engagement with theappliance, usually along the liner of the appliance or other chamber ofthe appliance. Typically, the module engages the inner surface of theliner of the appliance 34 and the mating elements of the appliance arealong the inward facing surfaces 36 of the liner mutually facing oneanother. Typically, the module is held in engagement with the applianceat least partially, more typically substantially or entirely by pressurefit between the inward facing surfaces of the appliance and the sides ofthe module.

Typically, the upper portion of the module has at least one snap releasereceiving groove 38 along the sides of the module for receiving/engaginga push button snap release element 40 of a covering component 42 thatmay optionally contain a control panel 44 or be configured to allowaccess to a control panel that is a part of the module through anaperture/window 46 (typically along the user facing surface of themodule) when the covering component is engaged to the upper portion ofthe module. The covering is held in place at least partially by at leastone biased component, but more typically two or more biased components39 that frictionally engage the covering component, typically along thesides. Usually, the covering component contains at least one coverappendage 48 along each side of the covering component that operativelyconnects/engages upwardly extending cover receiving grooves 50 along thesides of the upper portion of the module.

Typically, the front/user facing surface of the lower portion of themodule is solid and typically will contain a projection portion 52 thatalso forms a recessed portion 54 in the opposite rearward facing side ofthe module. The lower portion of the module also typically contains auser removable gas canister cover 56 that covers the gas canister(s) orreceptacles from view when the canister engages with the gas-canisterreceiving inlet. The lower portion of the module also typicallyincorporates a user-facing tray 59 that is typically capable ofsupporting the food retaining compartment/space with or without foodwithin the compartment. The tray also typically contains an optionallyremovable lattice structure 60 to allow small food components to fallbetween the spaces in the gridwork. Typically the lattice structure issized to fit within the entire tray but conceivably only a portion ofthe tray may include a lattice structure and the remainder of the traymay be flat and smooth or the tray could be entirely flat and smooth.Also, the tray could be textured to provide a slip resistant surface.

As can be seen in FIGS. 3-4, the rearward facing surface of the moduletypically contains an upper portion rearward-side cover 62 that coversthe main operating elements of the module contained within the upperportion of the module. The rearward-side cover 62 is typically held inplace with at least one, more typically a plurality of fasteners such asscrews 64. Typically the rearward side of the upper portion also has anappliance/power connector 66 that receives the connection from theappliance or other power source for the electrical power of the module.

As shown in FIG. 4, the upper portion of the module typically containsor is proximate at least one gas receiving inlet 68. The gas receivinginlet is typically spaced just within the lower portion of the module toallow easy connection of the canister through a typically circularaperture in the dividing wall 70 between the upper portion and the lowerportion of the module. Conceivably, a plurality of gas receivinginlets/connections can be utilized to receive a variety of different gascanisters. The gas canisters typically have a volume of about one literor less. The gas canisters and inlet(s) may be configured such that thegas canisters will only release gas when engaged to an inlet of themodule without damaging the canister. The canisters and/or inlet may beconfigured such that when the canister(s) is(are) operatively connectedto the inlet, the control device senses the type of gas contained withinthe canister. The module is also able to estimate or measure the amountof gas remaining in the canister that is connected to the inlet. The gascanisters may contain one of many different types of gases used tocreate a final modified atmosphere or may contain a mixture of gasespreblended to form a given modified atmosphere that best extends thelife of a given food product. It is also possible that the gas canisterwill contain a single gas that is the only gas used to create themodified atmosphere.

Typically, the gas proceeds through the inlet and then through apressure reducer 72 when gas is being supplied to the module. Thepressure reducer is typically engaged with the upper portion of themodule or held in place using a substantially C-shaped retainer 80 withtwo flat surfaces 82. The two flat surfaces typically each receive atleast one fastener, typically a screw, which also engages the upperportion of the housing of the module on the interior surface. The upperportion also typically contains one or more valves 74 that are typicallysolenoid valves as well as a vacuum pump 76. A substantially C-shapedvacuum pump bracket 86 with two substantially flat ledges retains thevacuum pump within the housing using fasteners, typically screws thatengage the vacuum pump bracket and the housing. Optionally, a secondvacuum pump stabilizing bracket 88 can be used to further stabilize thevacuum pump within the housing. Tubing 78 capable of having gas movewithin it typically is used to distribute the gases and may beinterconnected using connectors and/or one or more T-junction connectors84. Typically, electrical wiring is used to distribute power to theelectrically powered elements of the module, including the solenoidvalves, the control device, and the vacuum pump.

The upper portion of the module also typically contains at least onecontrol device that is typically a control board in combination with arelay or a microcontroller. A microcontroller is a functional computersystem on a chip that typically contains a processor core, memory, andprogrammable input/output peripherals. The memory may be RAM, programmemory or both. The control device is typically connected with an inputreceiving device for receiving instructions from a user. Typically theinput from the user in the case of the module of the present inventionis a control panel with push button or touch sensitive controls. Theinput receiving device is configured to receive input from the userincluding what type of modified atmosphere is desired. The controldevice is configured to be responsive to input from the user thatinstructs the control device to perform steps based at least in partupon the user input. The control device typically operates to controlvarious other components of the module including the vacuum pump and theopening and closing of the valves. The control device, in the case of amicrocontroller, typically has memory that utilizes a calibration curvefor estimating the free volume in a container based upon the timenecessary to remove ambient air in the food retaining space to apredetermined level at least substantially below ambient pressure andalso based upon one or more characteristics of the vacuum pump (forexample, the vacuum pump's strength). Typically, the calibration curveis stored in the memory of the microcontroller. In this manner, thecontrol device can approximate when to turn off the vacuum pump andbegin to supply modified atmosphere to the food retainingcompartment/space.

Also, optionally, the module may contain one or more gas storagechambers typically within the module where the gas storage chamber(s)are operably connected to the food retaining compartment/space and thechamber(s) can be filled from individual corresponding inlets thatreceive a gas canister or can be filled through the use of one inlet andvalves, typically solenoid valves positioned outside each chamber suchthat one or more specified gas storage chambers are filled at a giventime from the gas canisters. The gas storage chamber could be used tosupply all or a portion of the modified atmosphere to the food retainingcompartment/space. When only a portion is supplied, the remainder of agiven gas for the modified atmosphere can be supplied from the gascanister engaged to the inlet.

The module may also contain a heat-sealing element, which operates toseal the bag, including a flexible bag when such bags are used at a foodstorage compartment/space. When utilized, the heat sealing element canbe positioned where most convenient to the user, typically in the upperportion of the module and accessible to the user, more typically alongthe front surface of the module and accessible to the user.

The module can also contain one or more sensors or switches. Thesedevices can be used to measure and/or detect when the desired pressurelevel is reached inside the food retaining compartment/space. In oneembodiment, a pressure senor can be used to measure the pressureproduced as a result of the gas or gases being filled into the foodretaining compartment/space. Even in the case of different gases, thesensor can monitor the pressure contribution of each gas filled insequence (see FIGS. 14-15). Another alternative is to use one or morepressure switches to detect when, during the modified atmosphereinjection process, the pressure rises to the appropriate level in thefood retaining compartment/space and stop the process. This is typicallyachieved through the use of at least two pressure switches, but coulduse one pressure switch that uses the hysteresis of the first switch todetect when to stop/start the process. Also, a standard switch can beutilized to estimate the free volume in the food retainingcompartment/space. In this instance, the time to empty or substantiallyempty the food retaining compartment is measured by the control device,typically a microcontroller. The microcontroller typically uses acalibration curve (container free volume vs. emptying time) for thespecific vacuum pump being utilized in the module to determine thecontainer free volume and therefore the amount of time to allow modifiedgas or mixture of gases to flow into the container to prepare themodified atmosphere at a predetermined pressure level. The sensor couldalso be a light or other optical sensor used to regulate the amount ofthe modified atmosphere by measuring, for example, the characteristicsof how much light is allowed to reach the sensor and/or how light isdeflected

As shown in FIGS. 14-15, switching on the vacuum pump at the time T₀,the container starts to empty at a decreasing rate because less gas isextracted by the pump over time. After time T₁-T₀, which depends on thevolume of the food retaining compartment/space, the pressure reaches thepredetermined vacuum level P₁. The microcontroller can use this time(T₁−T₀) to estimate the free volume inside the food retainingcompartment/space using the calibration curve. It is then possible tocalculate the amount of gas required to achieve the target pressure P₂.Typically, this is done by the microcontroller, which communicates withthe solenoid valve and the solenoid valve opens to allow gas flow fromthe gas storage chamber and/or gas canister. Similarly, the above can beused when various bottles of gases are used to fill the food retainingcontainer/space, which is typically the case when multiple canisters ofdifferent gas as opposed to a canister with a predetermined blend ofdifferent gases is used to create the modified atmosphere. In such acase, more than one valve (three valves a, b, and c are shown in FIG.15) are opened for a time interval corresponding to the amount of gasneeded to form the modified atmosphere. The valves are typically openedindependently in order to have the required gas mixture inside thecontainer. T_(2a)−T₁ is the opening time for the first valve,T_(2b)−T_(2a) is the opening time of the second valve, T_(2c)−T_(2b) isthe opening time for the third valve in FIG. 15. When forming themodified atmosphere it is typically desirable to keep the final modifiedatmosphere pressure less then atmospheric pressure to ensure theautomatic sealing of the food retaining compartment/space. Typically,the final modified atmosphere pressure is about ½ atmospheric pressureor about ½ atmospheric pressure or less.

The modified atmospheres for use over food products according to anembodiment of the present invention include a modified atmosphere for ameat product, a dairy product, a fruit product, a vegetable product anda fish product. The modified atmosphere may be either oxygen rich orhave a reduced oxygen content compared to ambient air. Also, themodified atmospheres of the present invention also typically operate toreduce both aerobic and anaerobic pathogens in the food stored under themodified atmosphere. The modified atmosphere for the meat producttypically contains about 70% by volume oxygen, about 20% by volumecarbon dioxide, and about 10% by volume nitrogen. The modifiedatmosphere for the fish product typically contains about 40% by volumecarbon dioxide and about 60% by volume nitrogen. The modified atmospherefor fruits or vegetables typically contains from about 3% to about 10%by volume oxygen, from about 3% to about 10% by volume carbon dioxide,and from about 80% to about 94% by volume nitrogen. The modifiedatmosphere for dairy products typically contains from about 10% to about30% by volume carbon dioxide and from about 70% to about 90% by volumenitrogen. Applicants also believe that a modified atmosphere can be usedfor medications. For example, medications that might be prone tooxidation might have their shelf life improved by being stored in acontainer with a modified atmosphere with reduced oxygen content toprevent or retard oxidation. The modified atmosphere is typically overthe medication.

A method of producing a modified atmosphere within a rigid containertypically includes the steps shown in FIG. 16 and described below.First, a food to be stored under a modified atmosphere is placed withinthe container. Next, the rigid container is engaged to the modifiedatmosphere module. This can be by a screw-type engagement with the lidof the container or by other sealing type arrangement. Typically, arigid container uses at least one valve to allow gas flow into and outof the container. Next, the user activates the module by pressing the“start” button on the control panel, which is typically located on thefront of the module. The control device, a control board with a relay ora microcontroller, then switches on the vacuum pump and solenoid valveto allow gas to flow out of the container. Typically, a pressure switchdetects the pressure level inside the container. When the pressure levelreaches a level at or below at least about 500 mBar, the pressure switchsends a signal to the control device and the control device records thevacuum time and turns off the vacuum pump and solenoid valve. Next, thecontrol device switches the solenoid valve blocking the flow of gas fromthe compressed gas cylinder into the open position and the gas or gasmixture is allowed to flow into the container. Typically, the gas is agas mixture of preblended gas for a given modified atmosphere that isdesired. The control board then switches off the solenoid valve after atime interval depending on vacuum time. Optionally, multiple vacuum andgas injection process can be used to obtain the desired gas compositioninside the container. Finally, the container that has the modifiedatmosphere is sealed and removed from engagement with the module.

A method of producing a modified atmosphere within a (flexible) bagcontainer typically includes the steps shown in FIG. 17 and describedbelow. The bag is attached to the module and the user pushes the “start”button. The control device switches on the vacuum pump and the solenoidvalve thereby allowing gas to flow out of the bag. The vacuum pump pullsthe gas from within the bag. When the pressure level reaches a level ator below at least about 500 mBar, the pressure switch sends a signal tothe control device and turns off the vacuum pump and solenoid valve.Next, the control device switches the solenoid valve blocking the flowof gas from the compressed gas cylinder into the open position and thegas or gas mixture is allowed to flow into the bag. Typically, the gasis a gas mixture of preblended gas for a given modified atmosphere thatis desired. Optionally, multiple vacuum and gas injection processes canbe used to obtain the desired gas composition inside the bag. Thecontrol board then switches off the solenoid valve after about 5seconds. Next, the control device typically turns on the heat sealer forabout 7 seconds or for such time as necessary to form an air tight sealon the bag. Finally, the container that has the modified atmosphere isremoved from engagement with the modified atmosphere module.

While a vacuum pump is typically used to draw ambient gas from withinthe food retaining compartment/space and the gas forming the modifiedatmosphere thereafter added to the food retaining compartment/space, itis also possible to form a modified atmosphere according to anotherembodiment of the present invention by using overpressure of modifiedatmosphere to force out the amount of ambient gas and replace thisambient gas with the modified atmosphere.

In another aspect of the present invention, the present inventionincludes a kit that typically includes at least: (1) at least one gascanister containing a gas or a blend of gases where the gas canister iscapable of engaging a mounting location of a module and wherein themodule is capable of being mounted to an inner liner of an appliancecontaining a refrigerator space and the appliance provides electricalpower to the module and the module uses the gas or blend of gases fromthe canister to provide a modified atmosphere to food contained within afood retaining space that is re-sealably air tight; and (2) instructionsthat are transmitted to the user of the gas canister or canisters toengage the gas canister with the mounting location of the module. Theinstructions can be transmitted along with the gas canister or canistersor via a network of computers such as the Internet via a web site or webpage hosted on a computer server accessible over the Internet. Also, asdiscussed above, the canister(s) can be constructed with an engagementoutlet that will only allow air flow from the canister without damagingthe canister when the canister is connected with the inlet of themodule.

The above description is considered that of the preferred embodimentsonly. Modifications of the invention will occur to those skilled in theart and to those who make or use the invention. Therefore, it isunderstood that the embodiments shown in the drawings and describedabove are merely for illustrative purposes and not intended to limit thescope of the invention, which is defined by the following claims asinterpreted according to the principles of patent law, including theDoctrine of Equivalents.

1. An appliance system comprising: a food retaining space having avolume within the space; a module removably connectable to an applianceand comprising a housing, a controlling device, a switch, at least onevalve, a vacuum pump, and a gas inlet wherein the switch, the valve, andthe vacuum pump are each in communication with the controlling devicewherein the controlling device comprises a controlling device selectedfrom the group consisting of a microcontroller and a control board incombination with a relay; and wherein the valve is positioned betweenthe gas inlet and the switch, the food retaining space and the vacuumpump such that compressed gas cannot flow past the valve when the valveis in the closed position and compressed gas can flow into the foodretaining space when the valve is in the open position; and at least onecompressed gas containing receptacle that includes all or a portion of amodified atmosphere to be added to the food retaining space.
 2. Theappliance system of claim 1, wherein the control device comprises amicrocontroller wherein the microcontroller further includes a processorcore, memory, and programmable input and output peripherals wherein thememory stores an algorithm that utilizes a calibration curve forestimating the free volume in a container based upon the time necessaryto remove ambient air in the food retaining space to a predeterminedlevel at least substantially below ambient pressure and also based uponthe vacuum pump and wherein the microcontroller controls the opening ofthe valve for a time period to reach an amount of gas within the foodretaining space corresponding to a target pressure for the modifiedatmosphere within the food retaining space and wherein the targetpressure is less than ambient pressure.
 3. The appliance system of claim2, wherein different modified atmospheres are capable of being producedand maintained within the food retaining space at different times andwherein the appliance system further comprises an appliance.
 4. Theappliance system of claim 3, wherein the different modified atmospheresinclude a separate atmosphere for meat, fish, fruits, vegetables, anddairy products and wherein the module is removably engaged to an innerlining of a door of the appliance and the appliance includes arefrigerator compartment and the appliance supplies electrical power tothe module.
 5. The appliance system of claim 3, wherein the differentmodified atmospheres comprise a reduced oxygen content atmosphere and asubstantially increased oxygen content atmosphere relative to ambientair content.
 6. The appliance system of claim 5, wherein the vacuum pumpis operatively connected to remove ambient air from the food retainingspace when activated and when the valve for regulating the removal ofgas is opened.
 7. The appliance system of claim 1, wherein the modulecomprises a plurality of gas inlets and a plurality of valves positionedbetween the gas inlets and the food retaining space wherein the valvesallow gas to flow into the food retaining space when in the openposition and wherein each gas inlet receives a different compressed gascontaining receptacle.
 8. The appliance system of claim 7, wherein gasfrom a plurality of gas containing receptacles produces the modifiedatmosphere in the food retaining space by either using gas from onecylinder that includes a predefined modified atmosphere or using gasfrom a series of receptacles wherein each gas containing receptacle usedto produce the modified atmosphere has a different gas type within it.9. The appliance system of claim 8, wherein the valves are solenoidvalves controlled by the controlling device.
 10. The appliance system ofclaim 9, wherein the controlling device comprises a control board incombination with a relay that together controls the activation of thevalves.
 11. The appliance system of claim 10, wherein the module furtherincludes a pressure reducing apparatus operatively engaged to at leastone of the inlets.
 12. The appliance system of claim 11, wherein themodule includes a pressure reducing apparatus operatively engaged toeach of the inlets.
 13. The appliance system of claim 1, wherein themodified atmosphere contained in the food retaining space is at apressure less than the ambient pressure of the food retaining space. 14.The appliance system of claim 13, wherein the module is powered by theappliance when operatively connected to the appliance and wherein theappliance comprises an appliance selected from the group consisting of arefrigerator, a refrigerator and freezer, a freezer, and a countertopfaçade sized to receive the module and wherein the module furtherincludes a heat sealing apparatus for sealing the food retaining spaceafter the modified atmosphere is added to the food retaining space andwherein the food retaining space comprises a food retaining space chosenfrom the group consisting of a heat-sealable plastic bag, a fixed volumecontainer with at least one valve, a fixed geometry container with atleast one moveable geometric feature so that the volume can be expandedor contracted and at least one valve, and a fixed volume compartmentwithin the module having at least one valve.
 15. The appliance system ofclaim 14, wherein the module further comprises a control panel that theuser can view and interact with when the module is engaged to anappliance wherein the module receives user input via the control paneland the control panel is communicatively engaged with the controllingdevice.
 16. A method of providing a modified atmosphere to a foodstorage space having a volume for enhancing the preservation of foodstored in the food storage space when the food storage space containsthe food and the modified atmosphere comprising the steps of: providing:a food storage space having a volume within the food storage space; amodule removably connectable to an appliance and comprising a housing, acontrolling device, a switch, at least one valve, a vacuum pump, and agas inlet wherein the switch, the valve, and the vacuum pump are each incommunication with the controlling device and the controlling devicecomprises a controlling device selected from the group consisting of amicrocontroller and a control board in combination with a relay; andwherein a valve is positioned between the gas inlet and the switch, thefood storage space and the vacuum pump such that compressed gas cannotflow past the valve when the valve is in the closed position andcompressed gas can flow into the food storage space when the valve is inthe open position; and at least one compressed gas containing receptaclethat includes all or a portion of a modified atmosphere to be added tothe food storage space; engaging the food storage space with the modulesuch that gas is allowed to flow into and out of the volume within thefood storage space; activating the module such that the valve positionedbetween the gas containing receptacle and the switch, the food storagespace and the vacuum pump closes, the vacuum pump removes ambient airwithin the food storage space until a predetermined vacuum level isreached, the valve positioned between the gas containing receptacle andthe switch, the food storage space and the vacuum pump is opened, gasflows from the compressed gas containing receptacle into the foodstorage space to thereby create a modified atmosphere within the foodstorage space; and sealing the modified atmosphere and any food withinthe food storage space, within the food storage space.
 17. The method ofclaim 16, wherein the controlling device estimates the volume within thefood storage space using an algorithm based at least upon one or morefeatures of the vacuum pump and the time from when the vacuum pump isactivated until the predetermined vacuum level is reached and whereinthe controlling device communicates with the vacuum pump and the valvepositioned between the gas containing receptacle inlet and the switch,the food storage space and the vacuum pump to activate and deactivatethe vacuum pump and to actuate the valve between the closed and openpositions and wherein the controlling device uses the estimated volumewithin the food storage space to regulate the amount of modifiedatmosphere supplied to the food storage space.
 18. The method of claim17, wherein the amount of modified atmosphere supplied to the foodstorage space is no more than about half of the estimated volume withinthe food storage space.
 19. The method of claim 16, wherein the moduleuses a plurality of separate compressed gas containers to produce amodified atmosphere within the food storage space.
 20. The method ofclaim 18, wherein the module further comprises a plurality of gas inletseach capable of receiving a compressed gas cylinder wherein the volumeof each compressed gas cylinder is about one liter or less.
 21. Anappliance system comprising: a food retaining space having a volumewithin the space; and a module removably connectable to an appliance andcomprising a housing, a controlling device, a switch, at least onevalve, a vacuum pump, and a gas inlet wherein the switch, the valve, andthe vacuum pump are each in communication with the controlling devicewherein the controlling device comprises a controlling device selectedfrom the group consisting of a microcontroller and a control board incombination with a relay; and wherein the valve is positioned betweenthe gas containing receptacle inlet and the switch, the food retainingspace and the vacuum pump such that compressed gas cannot flow past thevalve when the valve is in the closed position and compressed gas canflow into the food retaining space when the valve is in the openposition; and at least one compressed gas containing receptacle thatincludes a predetermined blend of gases for a given type of food productwherein the food product comprises a food product chosen from the groupconsisting of a meat product, a dairy product, a fruit product, avegetable product, and a fish product and wherein the modifiedatmosphere for the meat product contains about 70% by volume oxygen,about 20% by volume carbon dioxide, and about 10% by volume nitrogen;the modified atmosphere for the fish product contains about 40% byvolume carbon dioxide and about 60% by volume nitrogen; the modifiedatmosphere for fruits or vegetables contains from about 3% to about 10%by volume oxygen, from about 3% to about 10% by volume carbon dioxide,and from about 80% to about 94% by volume nitrogen; and the modifiedatmosphere for dairy products contains from about 10% to about 30% byvolume carbon dioxide and from about 70% to about 90% by volumenitrogen.